1;;; parse-time.el --- parsing time strings 2 3;; Copyright (C) 1996, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007 4;; Free Software Foundation, Inc. 5 6;; Author: Erik Naggum <erik@naggum.no> 7;; Keywords: util 8 9;; This file is part of GNU Emacs. 10 11;; GNU Emacs is free software; you can redistribute it and/or modify 12;; it under the terms of the GNU General Public License as published by 13;; the Free Software Foundation; either version 2, or (at your option) 14;; any later version. 15 16;; GNU Emacs is distributed in the hope that it will be useful, 17;; but WITHOUT ANY WARRANTY; without even the implied warranty of 18;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 19;; GNU General Public License for more details. 20 21;; You should have received a copy of the GNU General Public License 22;; along with GNU Emacs; see the file COPYING. If not, write to 23;; the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, 24;; Boston, MA 02110-1301, USA. 25 26;;; Commentary: 27 28;; With the introduction of the `encode-time', `decode-time', and 29;; `format-time-string' functions, dealing with time became simpler in 30;; Emacs. However, parsing time strings is still largely a matter of 31;; heuristics and no common interface has been designed. 32 33;; `parse-time-string' parses a time in a string and returns a list of 9 34;; values, just like `decode-time', where unspecified elements in the 35;; string are returned as nil. `encode-time' may be applied on these 36;; values to obtain an internal time value. 37 38;;; Code: 39 40(eval-when-compile (require 'cl)) ;and ah ain't kiddin' 'bout it 41 42(defvar parse-time-syntax (make-vector 256 nil)) 43(defvar parse-time-digits (make-vector 256 nil)) 44 45;; Byte-compiler warnings 46(defvar parse-time-elt) 47(defvar parse-time-val) 48 49(unless (aref parse-time-digits ?0) 50 (loop for i from ?0 to ?9 51 do (aset parse-time-digits i (- i ?0)))) 52 53(unless (aref parse-time-syntax ?0) 54 (loop for i from ?0 to ?9 55 do (aset parse-time-syntax i ?0)) 56 (loop for i from ?A to ?Z 57 do (aset parse-time-syntax i ?A)) 58 (loop for i from ?a to ?z 59 do (aset parse-time-syntax i ?a)) 60 (aset parse-time-syntax ?+ 1) 61 (aset parse-time-syntax ?- -1) 62 (aset parse-time-syntax ?: ?d) 63 ) 64 65(defsubst digit-char-p (char) 66 (aref parse-time-digits char)) 67 68(defsubst parse-time-string-chars (char) 69 (and (< char (length parse-time-syntax)) 70 (aref parse-time-syntax char))) 71 72(put 'parse-error 'error-conditions '(parse-error error)) 73(put 'parse-error 'error-message "Parsing error") 74 75(defsubst parse-integer (string &optional start end) 76 "[CL] Parse and return the integer in STRING, or nil if none." 77 (let ((integer 0) 78 (digit 0) 79 (index (or start 0)) 80 (end (or end (length string)))) 81 (when (< index end) 82 (let ((sign (aref string index))) 83 (if (or (eq sign ?+) (eq sign ?-)) 84 (setq sign (parse-time-string-chars sign) 85 index (1+ index)) 86 (setq sign 1)) 87 (while (and (< index end) 88 (setq digit (digit-char-p (aref string index)))) 89 (setq integer (+ (* integer 10) digit) 90 index (1+ index))) 91 (if (/= index end) 92 (signal 'parse-error `("not an integer" 93 ,(substring string (or start 0) end))) 94 (* sign integer)))))) 95 96(defun parse-time-tokenize (string) 97 "Tokenize STRING into substrings." 98 (let ((start nil) 99 (end (length string)) 100 (all-digits nil) 101 (list ()) 102 (index 0) 103 (c nil)) 104 (while (< index end) 105 (while (and (< index end) ;skip invalid characters 106 (not (setq c (parse-time-string-chars (aref string index))))) 107 (incf index)) 108 (setq start index all-digits (eq c ?0)) 109 (while (and (< (incf index) end) ;scan valid characters 110 (setq c (parse-time-string-chars (aref string index)))) 111 (setq all-digits (and all-digits (eq c ?0)))) 112 (if (<= index end) 113 (push (if all-digits (parse-integer string start index) 114 (substring string start index)) 115 list))) 116 (nreverse list))) 117 118(defvar parse-time-months '(("jan" . 1) ("feb" . 2) ("mar" . 3) 119 ("apr" . 4) ("may" . 5) ("jun" . 6) 120 ("jul" . 7) ("aug" . 8) ("sep" . 9) 121 ("oct" . 10) ("nov" . 11) ("dec" . 12))) 122(defvar parse-time-weekdays '(("sun" . 0) ("mon" . 1) ("tue" . 2) 123 ("wed" . 3) ("thu" . 4) ("fri" . 5) ("sat" . 6))) 124(defvar parse-time-zoneinfo `(("z" 0) ("ut" 0) ("gmt" 0) 125 ("pst" ,(* -8 3600)) ("pdt" ,(* -7 3600) t) 126 ("mst" ,(* -7 3600)) ("mdt" ,(* -6 3600) t) 127 ("cst" ,(* -6 3600)) ("cdt" ,(* -5 3600) t) 128 ("est" ,(* -5 3600)) ("edt" ,(* -4 3600) t)) 129 "(zoneinfo seconds-off daylight-savings-time-p)") 130 131(defvar parse-time-rules 132 `(((6) parse-time-weekdays) 133 ((3) (1 31)) 134 ((4) parse-time-months) 135 ((5) (100 4038)) 136 ((2 1 0) 137 ,#'(lambda () (and (stringp parse-time-elt) 138 (= (length parse-time-elt) 8) 139 (= (aref parse-time-elt 2) ?:) 140 (= (aref parse-time-elt 5) ?:))) 141 [0 2] [3 5] [6 8]) 142 ((8 7) parse-time-zoneinfo 143 ,#'(lambda () (car parse-time-val)) 144 ,#'(lambda () (cadr parse-time-val))) 145 ((8) 146 ,#'(lambda () 147 (and (stringp parse-time-elt) 148 (= 5 (length parse-time-elt)) 149 (or (= (aref parse-time-elt 0) ?+) 150 (= (aref parse-time-elt 0) ?-)))) 151 ,#'(lambda () (* 60 (+ (parse-integer parse-time-elt 3 5) 152 (* 60 (parse-integer parse-time-elt 1 3))) 153 (if (= (aref parse-time-elt 0) ?-) -1 1)))) 154 ((5 4 3) 155 ,#'(lambda () (and (stringp parse-time-elt) 156 (= (length parse-time-elt) 10) 157 (= (aref parse-time-elt 4) ?-) 158 (= (aref parse-time-elt 7) ?-))) 159 [0 4] [5 7] [8 10]) 160 ((2 1 0) 161 ,#'(lambda () (and (stringp parse-time-elt) 162 (= (length parse-time-elt) 5) 163 (= (aref parse-time-elt 2) ?:))) 164 [0 2] [3 5] ,#'(lambda () 0)) 165 ((2 1 0) 166 ,#'(lambda () (and (stringp parse-time-elt) 167 (= (length parse-time-elt) 4) 168 (= (aref parse-time-elt 1) ?:))) 169 [0 1] [2 4] ,#'(lambda () 0)) 170 ((2 1 0) 171 ,#'(lambda () (and (stringp parse-time-elt) 172 (= (length parse-time-elt) 7) 173 (= (aref parse-time-elt 1) ?:))) 174 [0 1] [2 4] [5 7]) 175 ((5) (50 110) ,#'(lambda () (+ 1900 parse-time-elt))) 176 ((5) (0 49) ,#'(lambda () (+ 2000 parse-time-elt)))) 177 "(slots predicate extractor...)") 178 179;;;###autoload 180(defun parse-time-string (string) 181 "Parse the time-string STRING into (SEC MIN HOUR DAY MON YEAR DOW DST TZ). 182The values are identical to those of `decode-time', but any values that are 183unknown are returned as nil." 184 (let ((time (list nil nil nil nil nil nil nil nil nil)) 185 (temp (parse-time-tokenize (downcase string)))) 186 (while temp 187 (let ((parse-time-elt (pop temp)) 188 (rules parse-time-rules) 189 (exit nil)) 190 (while (and (not (null rules)) (not exit)) 191 (let* ((rule (pop rules)) 192 (slots (pop rule)) 193 (predicate (pop rule)) 194 (parse-time-val)) 195 (when (and (not (nth (car slots) time)) ;not already set 196 (setq parse-time-val (cond ((and (consp predicate) 197 (not (eq (car predicate) 198 'lambda))) 199 (and (numberp parse-time-elt) 200 (<= (car predicate) parse-time-elt) 201 (<= parse-time-elt (cadr predicate)) 202 parse-time-elt)) 203 ((symbolp predicate) 204 (cdr (assoc parse-time-elt 205 (symbol-value predicate)))) 206 ((funcall predicate))))) 207 (setq exit t) 208 (while slots 209 (let ((new-val (and rule 210 (let ((this (pop rule))) 211 (if (vectorp this) 212 (parse-integer 213 parse-time-elt 214 (aref this 0) (aref this 1)) 215 (funcall this)))))) 216 (rplaca (nthcdr (pop slots) time) 217 (or new-val parse-time-val))))))))) 218 time)) 219 220(provide 'parse-time) 221 222;;; arch-tag: 07066094-45a8-4c68-b307-86195e2c1103 223;;; parse-time.el ends here 224